1. Field of the Invention
The present invention relates to a transport apparatus including a conveyer belt for attracting and conveying a recording medium and to a recording apparatus for recording on the recording medium conveyed by the transport apparatus.
2. Description of the Related Art
In general, inkjet recording apparatuses carry out recording by ejecting ink drops from a recording head onto a recording medium conveyed by a transport mechanism. The inkjet recording apparatuses have advantages in that the size of the recording head can be easily reduced, high-resolution images can be recorded at high speed, the running cost can be reduced, noise can be reduced because of a non-impact mechanism, and a color image can be easily recorded by using ink of a plurality of colors. In particular, full-line type inkjet recording apparatuses include a line-type recording head having a plurality of ejection nozzles arranged in the width direction of the recording medium. Therefore, the full-line type inkjet recording apparatuses can provide higher speed recording.
However, among the full-line type inkjet recording apparatuses, apparatuses including a plurality of line-type recording heads in the moving direction of the recording medium have a large distance between the furthest upstream recording head and the furthest downstream recording head. Therefore, if moisture content of the recording area of the recording medium increases, the recording medium could slightly lift. This prevents an ink drop ejected from a recording head from being put on a desired position, and therefore, the recording quality is degraded. Accordingly, to prevent this phenomenon, it is necessary to press the recording medium against the transport mechanism.
In order to press the recording medium against the transport mechanism, a method is widely known in which the transport mechanism includes an electrode, which is charged to generate an electrostatic force so as to attract the recording medium (refer to, for example, Japanese Patent Laid-Open No. 2002-284383).
On the other hand, recently, recording on both sides of a recording medium has been required in many cases in addition to recoding on only one side of a recording medium. When recording on both sides of a recording medium, a recording head first ejects ink onto the first surface and then ejects ink onto the second surface. In this case, since recording on the first surface increases moisture content of the recording medium, the recording medium could significantly swell and ripple (cockle). Thus, the recording quality on the second surface is degraded compared to single-sided recording. If the above-described conveying method is applied to the double-sided recording, the recording quality required at that time can be satisfied. However, recently, higher recording quality has been required.
In addition, if a conveying belt is used to convey the recording medium and if the conveying belt remains unused in the apparatus for a long period of time, permanent deformation may occur at a portion having a large curvature, such as a portion in contact with a transport roller.